Dynamo-electric machine



A. A. POLLOCK DYNAMO ELECTRIC MACHINE Jan. 5 1926.

Filed March 19 1925 inventor: Alan A. Pollock by W His Attorney.

Patented Jan. 5, 1926.

UNITED STA'l.'.E$

PATENT OFFICE.

ALAN ADAIR BULLOCK, OF LEAMINGTON SPA, ENGLAND, ASSIGNOR TO GENERAL ELEG- TRIC COMPANY, A. CGRPORATION OF NEW YORK.

DYNAIVIO-ELECTRIC MACHINE.

Application filed. March 19, 1925. Serial No. 16,652.

To (17/ 10710922. it may concern:

Be it known that I, ALAN ADAM: PoLLooK, a subject of the British Empire, residing at Leamington Spa, England, have invented certain new and useful Improvements in DynamoElectric Machines, of which the following is a specification.

This invention relates to dynamo electric machines and more particularly to machines of the commutating type. In such machines it is desirable, when the current per circuit is large, to divide the current, commuted at any particular commutator segment, between a plurality of slots, as by this means greatly improved commutating conditions can be obtained and consequently the limit of capacity for successful commutation can be raised.

According to the present invention thls division of the current is effected by proiding an armature winding comprising coils, in each of which the current in one conductor is divided into two and returns through.two conductors which are in parallel and situated 360 electrical degrees apart, each parallel path being located 180 electrical degrees away from the first mentioned conductor. ith this arrangement of armature winding, any coil under commutation will come under the influence of three com mutating poles, so that there will be a tend ency towards self-equalization making it ru'inecessaiy to provide equalizer connections. I

For a. better understanding of my inverttion, reference may be had to the following description taken in connection with the accompanying drawing, in which Fig. l is developed plan view of a portion of an. armature winding embodying my inven-- tion; Fig. 2 shows a modified form of coil of an armature winding embodying my in" vention, the shape of the coil being different than that shown in Fig. 1; Fig. 3 is an end sectional view of my armature winding arranged as a four layer winding, and. Fig. l is an end sectional view of my armature wihding arranged as a three layer winding.

, Referring to Fig. 1 of the drawing, there is shown an armature winding connected to a commutator 1, the armature winding com prises coils, each or which comprises a plu rality of conductors 2, 3 and l. Two of the conductors, that is conductors 2 and 3, are located substantially 360 electrical degrees,

or two pole pitches, apart, and the other conductor 4- is located substantially 1S0 electrical degrees, or one pole pitch, from the first mentioned conductors 2 and 3. One complete coil is shown as covered with in sulation. In this figure certain of the end windings form straight extensions of the conductors in the slot and other end windings form extensions which are offset a full pole pitch. A four layer winding is shown in this figure and in Fig. 3, coil A being placed in the bottom of the slot and coils B, C and D, forming the second, third. and fourth layers, respectively. The order in which the layers are put into the slot may be varied as desired. By arranging the coils as shown, the coil pitch covers two pole pitches and the current which flows through conductor 4: divides and flows through the two paths formed by conductors 2 and The ends of conductors 2, and at the commutator end of the armature are connected to the commutator 1.

The form of coil shown in Fig. 2 is similar to that shown in Fig. 1, except for the curl connections. in this figure, conductors 2 and 3 are spaced 360 electrical degrees apart and conductor 4- is located 80 electrical degrees from both conductors 2 and S5 3. The end cormections of conductors 9. and 3' at both ends of the arn'iature are oll set a full pole pitch, whereas conductor l is substantially straight from end to end. The current flowing through conductor -l divides and flows through. the two paths formed by conductors 2 and 3.

The conductor l in Fig. l and the conductor at in Fig. 2 should have a cross section substantially twice that of the other conductors since it carries twice the current. Each of the conductors 4 or 4 may be made as a single conductor or as two separate conductors in parallel. In Figs. l and 3 they are shown as separate conductors, whereas in Figs. 2 and at they are shown as single conductors.

The coils of my armature winding have two conductors, 2 and 3 in Fig. l, and 2 and 3 in Fig. 2, in parallel generating substantially the same voltage which is added to the Cit voltage generated in conductor 4: in Fig. 1. and at. in F 2. The closed loop formed by conductors 2 and 3 or 2 and 3 being two pole pitches apart, serves as an equalizer to equalize the flux in the poles and thus equalize the voltage generated in the parallel circuits in the armature. Those closed loops are distributed completely around the armature and equalize the flux at all points, in the same way as the usual equalizer connections heretofore in use on dynamo electric machines of the commutatng type.

A lap winding has been illustrated in the drawings, but it is obvious that the invention is equally applicable to a wave winding.

The type ot' coil shown in Fig. 1, in which the end connections are straight extensions of the slot portions particularly lends it self to the slot insulation being carried right out to form the end winding insulation and can conveniently be moulded, thus keeping a continuous insulation throughout the slot and end winding. By suitably arranging the various layers of winding, this end winding with moulded insulation can be placed between two layers with offset windings, thereby materially improving he insulation between layers. Again, by arranging the straight end windings at the bottom layer of the winding, a series of axial air channels are formed between the lower layers and the top layers thereby materially improving the ventilating conditions of the winding i To retain both the advantages of in creased insulation and increased ventilation, a four la er winding may be arranged as shown in Fig. 3. In this arr; a, at the winding shown in Fig. l is employed. the

conductor consisting of two :ea'epa conductors in parallel. One oi ctors 4 is arranged between the C(HltltlttOlS fl and 3 as shown, and the other conductor t is arranged beneath the conductor l ig. lillustrates a three layer winding employing the form 0t coil shown in Fig.

QQthc conductor l consis ng of asingle conductor bar. Conductors El and 3 term the first and second layers respectively, the third or bottom layer oi the windings being the straight conductors t, which have double the cross section oi the conductors lshown in Fig.

I desire it to be understood that my invention is not limited to the particular arrangement shown and described and l aim in the appended claims to cover all modifications which do not depart from the spirit and scope of my invention.

lVhat I claim as new and desire to secure by Letters Patent of the United States, is

1. A dynamo electric machine of the commutating type, having an armature Winding comprising coils, each coil comprising a plurality of conductors, two of said conductors of each coil being located substantially 360 electrical degrees apart and another of said conductors of each coil being located substantially 180 electrical degrees from each of said first mentioned conductors.

2. A dynamo electric machine of the commutati-ng type, having an armature winding con'iprisi'ng coils, each coil comprising a plurality of conductors, two of said con ductors of each coil being located substantially 360 electrical degrees apart and another of said conductors of each coil being located substantially 180 electrical degrees from each of said first mentioned conductors, each of said coils providing a path for current which flows through said last mentioned conductor and then divides and flows through the two paths formed by said first mentioned condu tors.

mutator and an armature winding, said armature winding comprising coils, each coil comprising a plurality of conductors, two of said 'onductors of each coil. being substantially 360 electrical degrees apart and another oi said conductors of each coil being located substa Pally 180 electrical degrees from each 0 tirst mentioned r s 1(1 conductors, the ends of said conductors at the conuuutai'or end 01' said :u'inature being connected to said commutator.

A dynamo electric machine having an ire, said filP itill'e comprising a commutator and an rn'iatu winding, said armature winding comprising coils, each coil comprising a plurality of conductors, two of said conductors oi. each coil being substantially 360 electrical degrees apart and another of said conductors of each coil being located suostantially 180 electrical degrees from each ot said first mentioned conductors each of said coils providing a path for current which flows through said last mentioned conductor and then divides and flows through the two paths termed by said first mentioned conductors, the ends ct said conductors at the commutator end of said armature being connected to said commutator.

In witness whereoit, l. have hereunto set my hand this twenty-seventh day of February, 1925.

ALAN ADAIR POLLOCK.

DISCLAIMER 1,568,692.Alan Adair Pollock, Leamington Spa, England. DYNAMO-ELECTRIC MACHINE. Patent dated January 5, 1926. Disclaimer filed October 24, 1930, by the assignee, General Electric Company.

Hereby enters this disclaimer to claim 1 of said patent which is in the following wor s:

1. A dynamo electric machine of the commutating type, having an armature Winding comprising coils, each coil comprising a plurality of conductors, two 01' said conductors of each coil being located substantially 360 electrical degrees apart and another of said conductors of each coil being located substantially 180 elec trical degrees from each of said first mentioned conductors.

[Oflicial Gazette, November 18, 1.930]

DISCLAIMER 1,568,692.Al(m Adair Pollock, Leamington Spa, England. DYNAMO-ELECTRIC MACHINE. Patent dated January 5, 1926. Disclaimer filed October 24, 1930, by the assignee, General Electric Company.

Hereby enters this disclaimer to claim l of said patent which is in the following Words:

1. A dynamo electric machine of the commutating type, having an armature Winding comprising coils, each coil comprising a plurality of conductors, two of said conductors of each coil being located substantially 360 electrical degrees apart 7 and another of said conductors of each coil being located substantially 180 electrical degrees from each of said first mentioned conductors.

[Ofiicial Gazette, November 18, 1.930] 

